The present invention relates to a method and apparatus for making three-dimensional objects, such as models, dies, moulds, and other three-dimensional products.
The invention is particularly applicable to the technique of making three-dimensional objects constituted of a large number of relatively thin layers bonded together each having the contour of a thin slice of the object. Many such methods have been developed over the years, but they recently have become of particular interest since they may be used to facilitate the design of three-dimensional objects using CAD (computer-aided-design) techniques, or to facilitate the manufacture of three-dimensional objects using CAM (computer-aided-manufacture) techniques. In the known methods, as illustrated for example in U.S. Pat. Nos. 2,015,457, 2,335,127, 2,345,240, 3,539,410, 3,932,923, 4,132,575, 4,298,414, 4,385,949, 4,474,722, 4,673,453, and 4,752,352 the individual layers are first contoured, and then the contoured layers are stacked and bonded together to form the three-dimensional object. However, such methods are generally not very precise since they involve a registration problem between the pre-contoured layers, and take a relatively long time because the layers are generally cut with vertical walls requiring very thin layers to achieve good accuracy (to avoid a "stepped" appearance).
An object of the present invention is to provide a method and apparatus for making such three-dimensional objects which more readily lend themselves to CAD and CAM techniques and which may be used for producing three-dimensional objects with high precision and in a much shorter time than the above-mentioned existing methods.